Wheels and Tires

How big can I go on my rear tires without causing traction problems on the front. Today I have 275 / 35 / ZR18 on back Michelin Pilot Super Sports and 225/40/ZR18 Falken on front. Bummed the new rear tires wore out fast 18 months compared to front used over 3 years. I'm told that big on back can create front oversteer. So what should I do to optimize balance, treadwear and traction yet still have fun taking fast hard turns freeway or racetrack?

I installed a set of Michelin PS-2 tires about 3 months and 3,000 miles ago. Since then I have experienced 2 road hazard events which resulted in ruining the rear tires. My thinking is that if I had real time pressure monitoring, I may have been able to stop the car before the tire's destruction. My car did not come with a Tire Pressure Monitoring System.

I have Perrelli P Zero tires ( 18" ) right now and am getting ready to replace them . I'm looking for a better riding tire and understand that I will have to sacrifice some performance . I'm looking for reccomendations from fellow Porsche owners who have done the same or similar. Thanks everyone.

I have stock rims on a 2001 C4 with 225/40/ZR18 fr, 285/30/ZR18 rear Continentals.

I've read a several threads regarding wheel spacers with various widths, but I have a simple question: wouldn't it be best to do the same width (e.g. 15mm) both front and rear to maintain the same balance/handling characteristics Porsche intended? I've seen where it's been recommended to do "at least do 7mm in front to address the understeer" if someone is widening the rears, so I'm assuming doing a symmetrical change f/r would eliminate any alteration of that balance?

I replaced the rear tires with Pirelli P-O 285/30ZR18 about two years ago . The center of the tires in the rear only are badly worn . I never knew about summer & winter tires until I started looking for replacement tires . The front tires are fine . Any suggestions on replacing all 4 tires or just replace the rear tires ? I dont usually drive the car often in the winter but am I damaging the summer tires if I use them in the winter ? I put about three thousand miles a year on the car and mostly in the warm weather .